FIGURE 7.

Functional specificity of acetylases in ligand-activated FXR signaling. A, purified p300, CBP, pCAF, or GCN5, were incubated with GST-FXR and [³H]acetyl-CoA. The positions of acetylated FXR and FXR fragment are indicated by solid and dotted arrows, respectively. Auto-acetylated p300, CBP, and pCAF are indicated by asterisks. B, as a control, core histones (CH) were also incubated with each of acetylases and subjected to fluorography (upper panel) or Coomassie Blue staining (lower panel) after SDS-PAGE. C, HepG2 cells were cotransfected with Gal4-TATA-luc reporter and Gal4-DBD or Gal4-FXR in the presence of p300 or GCN wild type (WT) or catalytically inactive mutants (MT). Cells were treated with vehicle or 200 nm GW4064 overnight and harvested for reporter assays. The values for firefly luciferase activities were normalized by dividing by the β-galactosidase activities. The S.E. was calculated using the Student's t test (n = 3). D, mice were treated with GW4064 using oral gavage and 3-h later, liver were collected for ChIP assays as described in the legend to Fig. 3.